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1.0 INTRODUCTION
The Walchem WDB400 Series controllers offer conductivity control of boiler water and control of
chemical feed of two separate boilers. The chemical feed pump may be selected to operate in one of the
following modes:
Feed and Blowdown
Feed and Blowdown with Lockout
Feed as a percent of Blowdown
Feed as a percent of Time
Feed based on a Water Contactor input
The WDB series boiler controller is supplied with temperature compensated stainless steel electrodes with
a cell constant of 1.0. The controller is a microprocessor driven industrial type with on/off control
outputs. Timed intermittent sample or continuous modes may be selected. One or two optional 4-20 mA
outputs that are proportional to the conductivity reading are available for all models.
Any set point may be viewed without interrupting control. Each set point change will take effect as soon
as it is entered. An access code is available to protect set point parameters, while still allowing settings to
be viewed.
An alarm relay is provided that is triggered by:
Low conductivity reading
High conductivity reading
No flow situation
Sensor
error
Temperature
sensor
error
Blowdown
timeout
Our unique USB feature provides the ability to upgrade the software in the controller to the latest version.
An advanced USB capability option is available. The Config file feature allows you to save all the set
points from a controller onto a USB flash disk, and then import them into another controller, making the
programming of multiple controllers fast and easy. The data logging feature allows you to save the last
months readings and events to a USB flash disk.
